


Tumble

by mistilteinn



Series: At the end, you're not too bad [1]
Category: The Umbrella Academy (TV)
Genre: Anal Fingering, Anal Sex, Crossdressing, Explicit Sexual Content, M/M, Sibling Incest, we're all sinners here
Language: English
Status: Completed
Published: 2019-02-26
Updated: 2019-02-26
Packaged: 2019-11-05 23:04:59
Rating: Explicit
Warnings: Creator Chose Not To Use Archive Warnings
Chapters: 1
Words: 2,078
Publisher: archiveofourown.org
Story URL: https://archiveofourown.org/works/17928092
Author URL: https://archiveofourown.org/users/mistilteinn/pseuds/mistilteinn
Summary: Two times Diego notices Klaus in women's clothing, with vastly different outcomes.





	Tumble

**Author's Note:**

> The beginning bit takes place while they're still kids. No sex of any kind happens during this scene!!
> 
> All explicit bits take place when they're thirty, post-Reginald's death, but pre-apocalypse.

_One._

The first time Diego saw Klaus in women’s clothing was life-changing. They were young, twelve, maybe, and their dad was out of the house for a few hours, training (more likely arguing) somewhere with Five.

Allison and Luther were holed up in one of their rooms, not to be disturbed on penalty of physical punishment (Diego shuddered at the memory of the last time he bothered the two of them during Alone Time).

Vanya and Ben were with Mom in the kitchen, baking cookies. Diego knew because he’d just gotten kicked out of the little group for eating too much of the raw cookie dough. Vanya had cried, insisting that he’d get sick from it, and Mom had turned to him, gently suggesting he find someone else to play with.

So he was alone. Itchy, from the stupid uniform. Hot, because it was the middle of summer. He threw himself onto his favorite couch in the foyer, trying not to die from boredom, trying to come up with something fun to do. Maybe Pogo would play with him. He should check the lab.

He hauled himself up (no doubt creasing his stupid shorts) and shucked his blazer off, throwing it carelessly onto the couch cushions below, pausing for a second when he heard a familiar-unfamiliar sound from the staircase.

_Clip-clop. Clip-clop._

High heels. He heard that noise all the time - Mom wore heels around the house regularly. But - she was downstairs in the kitchen.

Brow wrinkled, Diego crept to the door and peeked around the corner, wishing that he had his knives.

His brain seemed to short-circuit when he saw Klaus. His annoying, beautiful, infuriating brother was twirling around at the top of the stairs in a dress and Mom’s heels, clacking happily away on the hardwood floor.

Diego’s jaw dropped as he stared at his brother; Klaus just spun, the skirt fluttering around him, his white calves flashing. He wobbled as he moved, unsteady in the too-big shoes, and tipped over the edge of the steps, tumbling gracelessly down.

Diego startled a shout and scrambled over to Klaus, who lay in a heap at the bottom of the steps. He shook his brother’s shoulder, terror icing its way through his veins when Klaus’s eyes didn’t pop open, when the corners of his mouth didn’t curl upwards into a mirthful smile.

“M-m-m-” Diego tried to get the words out, but they stuck in his throat. He tried again and again before wailing - partly out of frustration, partly out of fear for Klaus.

He didn’t remember much after everyone showed up. Luther carried Klaus’s limp form to the lab while Vanya and Ben took him up to his room.

* * *

 

_Two._

The next time he noticed Klaus in women’s clothing was also life-changing - but in a different way. A better way.

Diego stopped short upon entering the living room. Klaus lounged on the sofa, head rolling back as he giggled lightly to himself. His shirt was too small for him. It exposed a pale sliver of skin, jutting hip bones that made Diego’s mouth run dry. His ever-present fur and leather coat hung off of his shoulders and bunched beneath him. His skirt - it was something else. Short and shiny and rucked up even farther, showing off milky white thighs.

Klaus was - shameless was the only word to describe it. His dark kohl lined eyes met Diego’s, and his empty smile twisted into something smaller, more serious. Pupils unnaturally wide, he ran a hand through his messy brown hair and tilted his head, shifting in his seat to pull up his skirt ever so slightly and expose more tempting flesh.

Diego broke eye contact for a moment as he drank in the sight of his brother. He looked debauched. Face hot, when he met that calculating gaze once more, he knew he’d been caught.

The aimless amusement that had been previously present was gone without a trace. With a feline grace that belied his nonexistent sobriety, Klaus slinked right up to Diego and pressed in close, resting a hand on Diego’s chest. His eyelashes fluttered as he glanced down to Diego’s lips.

“So it’s still there, huh?” Klaus spoke in a low tone. Diego swallowed, nodding slightly. “Then what are you gonna do about it?” With that, Diego froze.

Klaus pulled back, running one long finger down his brother’s chest, and smiled brightly.

“Why now?” Diego managed, not sure if this was going to turn out to be one of Klaus’s stupid mind games.

His brother shrugged, the coat slipping off of his shoulder. “Why right now? You’re here, I’m bored, and it’s hot,” he murmured, drawing out the “o” sound in hot. Annoyingly, it kind of turned Diego on. Klaus smirked at him and continued. “Why in general? I’ve seen the way you look at me. Even when you’re pissed off, there’s a part of you that just wants to own me,” Klaus looked way too smug for his own good, “make me yours.”

Diego dropped his gaze, swallowing tightly and grimacing. His most guarded secret, out in the open. His deepest shame, and Klaus had known about it for how long?

Before he could sink deeper into himself, Klaus cupped his jaw with a gentle hand. “Hey,” he started, “I want to make this very clear. I want that too. I want you to take me apart, rearrange me how you want, and put me back together again when you’re done. I want to be yours, and I want you to be mine as well. I want you more than I want to get high again, and I _really_ want to get high.” Klaus blinked hard at that last bit, eyes clear and a little shiny. A smile curled its way across Diego’s face at his brother’s admission, and Klaus continued. “What do you say, big guy? You wanna do something about it?”

“Yeah, I fuckin’ do,” Diego spoke, bringing his hands up to curl around Klaus’s hips, thumbs massaging the bare skin. Feeling a little more confident, he let his gaze slowly track up and down Klaus’s body - his pale skin, the dip of his waist, that stupid coat covering too much. His grip tightened before he let go, instead moving to shove the coat off of Klaus’s slender frame. “God,” he gripped Klaus around the back of his neck and leaned in once more. “You’re so fucking beautiful.”

Klaus blinked, seemed to sway on his feet for a moment before leaning in and meeting Diego in the middle, catching the corner of his mouth and bringing his arms up to wrap around Diego’s shoulders.

Diego moved a hand beneath Klaus’s ridiculously tiny shirt and brushed over his stomach, taking advantage when Klaus let out a small “oh” and deepening the kiss. He licked into Klaus’s mouth, running his tongue over the back of his teeth and massaging his tongue with his own. Klaus gave as good as he got, following Diego’s lead enthusiastically. He pulled back for a giggle when their teeth clacked together and brought his hands to Diego’s chest before pushing him bodily onto the sofa where he’d been lounging about just a few minutes ago.

Klaus smiled at Diego’s surprised “oof” and clambered atop, straddling his hips and pressing down onto his half hard cock. Diego hissed at the pressure in his jeans and reached under Klaus’s skirt to grip his ass cheeks and haul him in closer.

“Fuck,” he started, pausing when Klaus fisted a hand in his shirt and sucked a hickey into his neck, toes curling at the combination of pain and pleasure. “No underwear?” He ran a finger down the crease of Klaus’s ass and circled his hole lightly.

“I’m an efficient man,” Klaus quipped and sat up, eyes rolling back as he pressed onto Diego’s finger, trying to find some relief. “You don’t put on a skirt like this if you’re not planning to get fucked.” He whined when instead of getting what he wanted, Diego pulled back, bringing his hand up in front of Klaus’s mouth.

“Suck,” he commanded. Klaus complied eagerly, eyes round as saucers. Diego struggled to unzip his jeans with the other hand, managing to free his cock by the time Klaus had saliva dripping down his chin. He pulled his fingers free with a _pop_ and wasted no time pressing up against Klaus’s hole, this time actually breeching the tight ring of muscle.

“Oh, shit,” Klaus scrunched his brow in a facsimile of pain, pushing desperately against Diego’s finger. “More, more, more,” he keened when Diego slipped a second finger in alongside the first and reached between them to grip both of their cocks in hand, using their precome as lubricant.

“What do you want? What do you need me to give you?” Diego bucked up into Klaus’s hand, using his free hand to ruck up the other man’s shirt and tweak a pebbled nipple.

“Please, fucking -” Klaus yelped and jumped when Diego brushed up against something spongey inside of him. Diego pressed again, harder, and Klaus sobbed out a “fuck.” He lost his rhythm, hand stuttering on their cocks. “Please, fuck me. I wanna be yours. I wanna feel it for days.”

“Fuck,” Diego responded eloquently, pulling his fingers free and grabbing Klaus harshly by the hips, lifting him over his cock.

“Please,” Klaus begged prettily, hiccoughing out a sob when his rim caught the head of Diego’s cock. He moaned as Diego dragged him down slowly, savoring every inch. Diego had to pause for a moment, fingers bruising Klaus’s hips, to keep from blowing his load right then.

When the wave of pressure in his gut subsided, Diego planted his feet and thrust upwards, pulling Klaus roughly down to meet him. He knew he wasn’t gonna last long, couldn’t last long with Klaus’s tight heat around him, those teary eyes screwed shut, his mouth open in a silent scream. Diego let go of Klaus’s hip with one hand and jerked him in time with his thrusts, groaning when Klaus came with a choked-off shriek, spilling all over Diego’s shirt.

Within just a couple of thrusts, that familiar heat was curling in his stomach and the muscles in his legs were tensing. The orgasm crashed into him like a wave at the ocean, shocking him with its intensity. He was pretty sure he blacked out for a second, because when he opened his eyes, Klaus was slumped over him without a thought for the come that would shortly start drying between both of their shirts.

Klaus moaned softly when Diego pulled his softening cock out of him and shivered at the sensation of come leaking out. Diego rubbed a hand over his back comfortingly, speaking when Klaus looked up at him. “You still need me to take care of you, huh?” Klaus nodded wordlessly, eyes already drooping, make up smudged beyond repair.

Diego carried him upstairs and ran a bath for him, placing him gently into the tub after tossing both of their soiled clothes in a heap to be dealt with later. Klaus was completely blissed out, letting Diego wash his hair, clean him up, and wrap him in a towel. He finally spoke as he watched the other man clean up (no bath, just a cursory wipe down). “I don’t even know what to say.”

Diego hopefully suggested, “You could say nothing at all?”

His brother rolled his eyes and a familiar smile wound its way across his face. “Yeah right, I was just being cute about it. That was absolutely, definitely, at least top ten fucks of my life right there.”

Diego froze when he spoke, glaring at Klaus. “Top _ten?”_ He stepped back over and scooped Klaus into his arms much less gently than before, ignoring his indignant squawk.

Klaus giggled - a high-pitched, slightly nervous sound. “Yeah, I mean, c’mon, we’ve never even fucked before. Top ten is pretty high praise, considering how many times - ah!” He was cut off when Diego dropped him unceremoniously onto his bed before shoving him over to make room. Klaus let him manhandle them into a comfortable cuddling position, drifting back towards the comfortable haze he’d been in after coming.

He couldn’t help but needle Diego one more time - he needed something prickly to counteract the warm softness he felt. “Okay, I lied. Definitely top five.”

Diego pinched him ruthlessly, holding him tight when he tried to wiggle away. “Stop. Talking.”

 

**Author's Note:**

> Let me know what you think! Your comments are incredibly motivating!!
> 
> If you have something specific for these guys that you'd like me to write about, just leave it below! 
> 
> (Also, the number of time I had to resist the urge to let Klaus call Diego "daddy" in this fic was absolutely ridiculous)


End file.
